As a Last Resort

You can reinstall Windows XP over a damaged Windows XP system. Doing so might be time-consuming, but reinstalling is useful if other repair attempts do not solve your problem. You should attempt an upgrade install first. If this works, you will have repaired your OS and retained your installed applications and most system configuration settings. If upgrading fails, you must perform a fresh install, which means you'll have to re-install all of your applications and remake all of your settings changes. Unless you format the drive, your data files will remain unaffected by the upgrade or fresh install process.

TIP

If you do a fresh install, you don't have to worry that your documents and settings will get wiped out. They won't. During a re-install, Windows XP setup checks to see if there are pre-existing Documents and Settings for each user account you create, and uses a modification of that name to create the new account settings. For example, my account name is Bob. So, under D:\Documents and Settings, there is a sub-folder called D:\Documents and Settings\Bob. When I did a fresh reinstallation on the same drive, and set up my user account again (using the name “Bob” once again), XP did not overwrite the existing Bob folder. Instead it created a new folder called D:\Documents and Settings\Bob.HP-Laptop. XP appended the name of my computer onto my username. Now all I had to do was fish around in files and folders under Bob (such as Desktop, Favorites, Cookies, Application Data, and so on) and copy those over to the new Bob.HP-Laptop folder. Then I was back in business.